Treated bitumen



Patented Nov. 6, 1934 OFFICE TREATED BITUMEN om a. Douthett, mane, N. 1., assignor to The Barber Asphalt Company, Philadelphia," Pa a corporation ofwut Virginia No Drawing. Original application June 8, 1928,,

Serial No. 284,003.

Divided and this application April 14, 1930, Serial No. 444,362

13 Claims. (CL 196-152) My invention relates to a method for the treat ment of bitumen whereby a. bitumen having a low degree of susceptibility to temperature changes may be produced. My invention also contemplates the bitumen having novel characteristics as produced by my process.

Heretofore it has been known that blowing bitumen, such as petroleum residuum, with air,

steam or inert gases, more particularly when air is used, has the effect of lowering somewhat its susceptibility to temperature changes, raising the melting and flowing temperatures of the bitumen andrendering it available for certain uses such as, for example, in the production of built-up roofs, prepared roofing materials, and for waterproofing and similar purposes requiring a bituminous material of low susceptibility. However, the bitumen so produced, while improved over untreated bitumen, is not as profoundlyaffected as so by the method in accordance with my invention and this further reduction in susceptibility makes my product more adaptable to commercial uses.

Now, in accordance with my invention I efiect the production of a bitumen having a relatively low susceptibility to temperature changes through the treatment of bitumen with a halogen in such limited proportion as to avoid any considerable reaction between the halogen and the hydrocarbons of the bitumen. More particularly, in accordance with my invention I subject bitumen to treatment with a halogen in small proportion and with air. Preferably the halogen is in the gaseous state and in admixture with air, the treatmentof the bitumen being edected by blowing it in a heated condition with the mixture.

In accordance with my invention the bitumen subjected to treatment may be, for example, asphalt, either native, or still residuum which may be of asphaltic, or paramn base, or mixed base. The halogen may be, for example, chlorine, iodine or the like, thoughchlorine will be found to be preferable.

In the carrying out of my invention preferably, as has been indicated, bitumen in a heated condition is blown with a mixture of air and a small proportion of a halogen in the gaseous state. The bitumen under treatment is preferably maintained at a temperature within about the range 450 F.-600 F. and the proportion of halogen used in the treatment will be, preferably, from a fraction of one per cent to about ten per cent by weight of the residuum treated. The rate of blowing oi the residuum 'may be varied widely, but a rate of for example, about thirty cubic feet of air per minute per ton of bitumen under treatment will be found to produce satisfactory results. The bitumen after treatment with the mixture of halogen and air may be advantageously blown with steam for the removal of unstable or volatile halogen compounds which may have been 50 formed. 7

As a more specific illustration of the practical adaptation of my invention, for example, a quantity of still residuum, which may be of asphaltic, or paraflin base, or mixed base, is placed in a cylindrical still provided in its bottom with a perforated pipe. The asphalt is heated to a temperature preferably within the range about 475 l t-525 F. and. air is introduced, as by a blower, into the asphalt through the perforated pipe at the rate of about thirty cubic feet per minute per ton of asphalt. A halogen, as for example chlorine, is introduced into the asphalt with the air in an amount of from a fraction of one per cent to about ten per cent by weight of the asphalt 7d and preferably in an amount less than about ten per cent. The halogen, as chlorine, may be readily introduced into the asphalt with the air by connecting a cylinder of liquefied gas to the air line, and the amount of halogen admitted may W be readily determined by means of a flow meter, or by periodic weighing of the'cylinder containing the liquefied gas.

As a specific example of the application of my invention, a quantity of asphaltic base petroleum 86 residuum, at a temperature of about 475 F'.--525 F. was blown for a period of about three-quarters of an hour with air containing in admixture chlorine in amount equal to about 7.1% by weight of the residuum treated. The blown residuum 90 was found to have a penetration, under 100 gram load for five seconds, of about .59 cms. at 77 F., about 1.83 ems. at a temperature of 122 F. and a ring and ball softening point of 175 F.

As a further example, a quantity of mixed base residuum, comprising a mixture of 87.5% asphaltic base residuum with 12.5% parafiine base residuum was blown with air admixed with 2.33% chlorine. The product was found to have a penetration, under gram load for five seconds, of 100 about 1.17 ems. at 77 F., of about 3.22 cms. at 122 F. and a softening point by the ring and ball method of 212 F.

As has been indicated, the bitumen after blowing may be desirably blown with steam, at say 450 F., for the removal of unstable or volatile chlorine compounds.

The treatmentof bitumen in accordance with my invention, with, forexample, a halogen, as chlorine, does not involve a substantial degree of chlorination so far as the composition of the new product is concerned, the concentration of chlorine being below that which would effect any substantial chlorination and consequent undesirable decomposition of the bitumen treated, which is avoided. The product produced in accordance with my invention, using chlorine equal to eight per cent by weight of residuum treated contained not more than 0.50% to 0.53% of chlorine. The halogen, as chlorine, in admixturewith the air apparently combines to some extent with the hydrogen of the bitumen, since some hydrochloric acid gas is evolved when chlorine is used, leaving the hydrocarbons in a very reactive condition such that they readily react with the oxygen of the air which is in admixture with the chlorine. The reaction is not primarily a chlorination, when chlorine is used, since chlorine compounds are not found in the product to any considerable extent, it having been determined that when say from six per cent to ten per cent of chlorine is used, the product will contain only a fraction of one per cent of chlorine.

The bitumen produced in accordance with my invention has characteristics which make it greatly superior to that obtained by theuse of air alone. The melting point and flowing temperature of the former is much higher for a given consistency than that of the latter, thus enabling its use for covering steep roofs, for waterproofing highly inclined surfaces and various purposes where being subject to elevated temperatures, bitumen treated by the use of air alone can not be satisfactorily used.

A marked improvement in bitumen produced in accordance with my invention, over that obtained by the use of air, is the low degree of susceptibility to temperature changes. That is the consistency, measured by the penetration, varies much less at different temperatures than does that of bitumen hitherto produced. Using as the initial material a mixture of residuums of an asphaltic with a paraffin base oil and proceeding in accordance with my invention a bituminous product is obtained having a higher melting point for a given penetration and a lower susceptibility than can, so far as I am aware, be obtained in any other way. Blowing such a mixture of residuums with air only, results in a product whichin a short time becomes very oily due probably to the separation of paraflln oil from the asphalt, which results in a loss of the adhesive property of the asphalt and renders it unsuitable for many purposes. Using a mixture of air-ands halogen, as chlorine, in accordance with my invention, a product is obtained which remains homogeneous indefinitely. with reasonable amounts of paraflin base oil present; when only very small amounts of chlorine are used. When several per cent of chlorine is used the product is stable with large amounts of paraflin base oil.

A further advantage in the use of ahalogen, as chlorine, mixed with air, in blowing bitumen, as native asphalt, a petroleum residuum, or the like, is the saving of time and power. For example, a residuum from an a'sphaltic base petroleum blown with air at the rate of 500 cubic feet per ton per minute, required 2% hours to produce an asphalt having a penetration of .59

"cms. under a load of 100 grams for 5 seconds at 77 F. A portion of the same residuum blown, under the same conditions, with air to which 7.1 per cent chlorine was added produced in hour anasphalt having a penetration of .54 cms. under identical conditions.

It will be understood that while, in the description of my invention, I have referred to percentages and temperature ranges, I do not thereby intend to limit my invention thereto, and it will be understood that my invention from the broad standpoint contemplates the treatment of bitumen with a halogen in amounts such as not to cause any considerable decomposition of the hydrocarbons of the bitumen, and more particularly, as by blowing with air in admixture with a halogen, the concentration of the halogen being insufiicient to efiect any considerable decomposition of the hydrocarbons of the bitumen. My invention is more particularly applicable to bitumen of the nature of asphaltic base, paraffin base and mixed asphaltic and parafiin base still residuum, mixtures of these with asphalt, asphalts, tars and any bituminous materials susceptible to modification by blowing with air. While I prefer to use chlorine, as a halogen, it will be understood that I may use other halogens as iodine, bromine or the like.

I do not herein claim the method disclosed, as such forms the subject matter of an application for United States Letters Patent filed by me June 8, 1928, Serial No. 284,003, of which this application is a division.

What I claim and desireto protect by Letters Patent is:

1. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and containing a halogen, obtained by treatment of bitumen with a halogen and a gaseous material furnishing oxygeni'said bitumen being substantially free from undesirable non-volatile halogen decomposition products.

2. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and containing chlorine, obtained by treatment of bitumen with chlorine and a gaseous material furnishing oxygen, said bitumen being substantially free from undesirable non-volatile chlorine decomposition products.

3. A bitumen having a low susceptibility to temperaturechanges, a high melting point for a given consistency and containing a halogen, obtained by treatment of bitumen with a halogen and air, said bitumen being substantially free from undesirable non-volatile halogen decomposition products.

,4. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and containing chlorine, ob-

tained by treatment of bitumen with chlorine andair, said bitumen being substantially free from undesirable non-volatile chlorine decomposition products.-

5. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and containing a halogen not in excess of about 53%, obtained by treat- ";gnent of bitumen with a halogen and air, said bitumen being substantially free from undesirable non-volatile halogen-bitumen decomposition products.

6. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and containing chlorine not in excess of about 53%, obtained by treatment of bitumen with chlorine and air, said bitumen being substantially free from undesirable nonvolatile chlorine-bitumen decomposition products.

7. A bitumen having a low susceptibility to temperature changes, a high melting point for a given consistency and substantially free from undesirable halogen-bitumen decomposition products obtained by the treatment of bitumen with a mixture of air and a halogen in which the amount of air is greatly in excess of the amount or free halogen.

8. A bitumen having a lowsusceptibility to temperature changes, a high melting point fora given consistency and substantially tree from undesirable chlorine-bitumen decomposition products obtained by the treatment of bitumen with a mixture of air and chlorine in which the I amount of air isgreatly in excess of the amount of free chlorine.

9; A mixed asphaltic and paraiiin base residuum having a low susceptibility to temperature changes, a high melting point for a given consistency and substantially free from undesirable halogen-bitumen decomposition products obtained by the treatment of bitumen with a mixture of air and a halogen in which the amount of air is greatly in excess of the amount of tree halogen.

A 10. A mixed asphalticnnd paramn base residuum having a low susceptibility to temperature changes, a high melting point for a given consistency and substantially free from undesirable chlorine-bitumen decomposition products obtained by the treatment of bitumen with a mixture of air and chlorine in which the amount or air is greatly in excess oi the amount oiiree chlorine;

composition products.

13. A bituminous residuum having a low susa '11. A mixed asphaltic mapmmn base residuum having a low susceptibility to temperature changes and a high melting point for a given consistency, containing a halogen in amount not in excess of about 53% obtained by treatment of bitumen with a halogen and a gaseous material furnishing oxygen and substantially free from undesirable non-volatile halogen-bitumen composition products.

12. A mixed asphaltic and paraiiin base residuumhaving a low susceptibility to temperature changes and-a high melting point for a given consistency, containing chlorine in amount not in excess of about .53% obtained by treatment of bitumen with chlorine and a gaseous material furnishing oxygen and substantially free from undesirable non-volatile chlorine-bitumen de- 

